Electroluminescent Display Device

ABSTRACT

An electroluminescent display device includes a substrate including a first pixel column and a second pixel column that respectively include first pixels and second pixels arranged in a first direction and respectively have a first width and a second width in a second direction, wherein the second pixel column is positioned in the second direction from the first pixel column, and the second width is greater than the first width; a light emitting diode in each first pixel and each second pixel and including a first electrode, a light emitting layer and a second electrode; a first bank positioned between adjacent first pixels and between adjacent second pixels and covering an edge of the first electrode; a second bank positioned between the first and second pixel columns; and a first partition wall across the second pixel column along the first direction and positioned on the first electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of Republic of Korea PatentApplication No. 10-2019-0172999 filed in the Republic of Korea on Dec.23, 2019, which is hereby incorporated by reference in its entirety.

BACKGROUND Field of Technology

The present disclosure relates to a display device, and moreparticularly, to an electroluminescent display device having a largesize and high resolution.

Discussion of the Related Art

An electroluminescent (EL) display device among new flat panel displaydevices is a self-emission type such that there are advantages in aviewing angle and a contrast ratio in comparison to a liquid crystaldisplay device. In addition, since a backlight unit is not required inthe EL display device, there are advantages of a thin profile and lowpower consumption.

The EL display device includes red, green and blue pixels, and the red,green and blue pixels respectively include red, green and blue emittinglayers.

Generally, each emitting layer may be formed by selectively depositingan emitting material through a vacuum thermal evaporation process usinga fine metal mask. However, since a mask, i.e., the fine metal mask, isrequired in the deposition process, the production cost is increased. Inaddition, the above deposition process is not adequate to fabricate anEL display device having a large size and high resolution.

SUMMARY

Accordingly, the present disclosure is directed to an electroluminescentdisplay device that substantially obviates one or more of the problemsdue to limitations and disadvantages of the related art.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present disclosure, as embodied and broadly described herein, anelectroluminescent display device includes a substrate including a firstpixel column and a second pixel column, wherein the first and secondpixel columns respectively include a plurality of first pixels and aplurality of second pixels arranged in a first direction andrespectively have a first width and a second width in a second directionperpendicular to the first direction, and wherein the second pixelcolumn is positioned in the second direction from the first pixelcolumn, and the second width is greater than the first width; a lightemitting diode in each first pixel and each second pixel and including afirst electrode, a light emitting layer and a second electrode; a firstbank positioned between adjacent first pixels and between adjacentsecond pixels and covering an edge of the first electrode; a second bankpositioned between the first and second pixel columns and extendingalong the first direction; and a first partition wall being across thesecond pixel column along the first direction and positioned on thefirst electrode.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a schematic circuit diagram of an EL display device accordingto one embodiment of the present disclosure.

FIG. 2 is a schematic plan view of a part of an EL display deviceaccording to a first embodiment of the present disclosure.

FIG. 3 is a cross-sectional view taken along the line I-I′ of FIG. 2according to one embodiment of the present disclosure.

FIG. 4 is a cross-sectional view taken along the line II-IP of FIG. 2according to one embodiment of the present disclosure.

FIG. 5 is a schematic plan view of a part of an EL display deviceaccording to a second embodiment of the present disclosure.

FIG. 6 is a schematic plan view of a part of an EL display deviceaccording to a third embodiment of the present disclosure.

FIG. 7 is a cross-sectional view taken along the line of FIG. 6according to one embodiment of the present disclosure.

FIG. 8 is a schematic plan view of a part of an EL display deviceaccording to a fourth embodiment of the present disclosure.

FIG. 9 is a schematic plan view of a part of an EL display deviceaccording to a fifth embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the preferred embodiments,examples of which are illustrated in the accompanying drawings.

FIG. 1 is a schematic circuit diagram of an EL display device accordingto the present disclosure.

As shown in FIG. 1, an EL display device includes a gate line GL, a dataline DL, a power line PL, a switching thin film transistor (TFT) Ts, adriving TFT Td, a storage capacitor Cst, and a light emitting diode D.The gate line GL and the data line DL cross each other to define a pixelregion P. The switching TFT Ts, the driving TFT Td, the storagecapacitor Cst and the light emitting diode D are formed in the pixelregion P.

The switching TFT Ts is connected to the gate and data line GL and DL,and the driving TFT Td and the storage capacitor Cst are connected tothe switching TFT Ts and the power line PL. The light emitting diode Dis connected to the driving TFT Td.

In the EL display device, when the switching TFT Ts is turned on by agate signal applied through the gate line GL, a data signal from thedata line DL is applied to the gate electrode of the driving TFT Td andan electrode of the storage capacitor Cst.

When the driving TFT Td is turned on by the data signal, an electriccurrent is supplied to the light emitting diode D from the power linePL. As a result, the light emitting diode D emits light. In this case,when the driving TFT Td is turned on, a level of an electric currentapplied from the power line PL to the light emitting diode D isdetermined such that the light emitting diode D can produce a grayscale.

The storage capacitor Cst serve to maintain the voltage of the gateelectrode of the driving TFT Td when the switching TFT Ts is turned off.Accordingly, even if the switching TFT Ts is turned off, a level of anelectric current applied from the power line PL to the light emittingdiode D is maintained to next frame. Accordingly, the EL display devicedisplays an image.

FIG. 2 is a schematic plan view of a part of an EL display deviceaccording to a first embodiment of the present disclosure.

As shown in FIG. 2, the EL display device 100 according to the firstembodiment of the present disclosure includes first to third pixels P1,P2 and P3. The different color pixels are arranged along a firstdirection X, and the same color pixels are arranged along a seconddirection Y. Namely, the first to third pixels P1 to P3, which aredifferent from each other, are sequentially arranged along the firstdirection X, and the first pixels P1, the second pixels P2, and thethird pixels P3 are respectively arranged along the second direction Y.For example, the first pixel P1 may be a red pixel, the second pixel P2may be a blue pixel, and the third pixel P3 may be a green pixel.

Since the second pixel P2 as the blue pixel has bad emitting properties,e.g., an emitting efficiency and/or a lifespan, the second pixel P2 hasan area (or size) being larger than each of the first and third pixelsP1 and P3. For example, the first to third pixels P1 to P3 respectivelyhave first to third widths W1, W2 and W3, and the third width W3 isgreater than the first width W1 and smaller than the second width W2.

A first bank 170 is disposed in a portion between adjacent same colorpixels arranged along the second direction Y. The first bank 170 isdisposed between adjacent first pixels P1, between adjacent secondpixels P2, and between adjacent third pixels P3. Namely, the first pixel170 extends between same pixels, which are adjacent along the seconddirection Y, along the first direction X. Alternatively, the first bank170 may be omitted.

A second bank 172 is disposed in a portion between adjacent two pixelamong the first to third pixels P1 to P3 in the first direction X. Thesecond bank 172 is disposed between the first and second pixels P1 andP2, between the second and third pixels P2 and P3, and between the thirdand first pixels P3 and P1. Namely, the second bank 172 extends betweendifferent pixels, which are adjacent along the first direction X, alongthe second direction Y. The second bank 172 has an opening incorrespondence to the same color pixels arranged along the seconddirection Y. The second bank 172 has a single opening in correspondenceto all of the first pixels P1, all of the second pixels P2 or all of thethird pixels P3 in one pixel column. Namely, the opening of the secondbank 172 extends along the second direction Y, and a length of theopening in the second direction Y is larger than a length of the openingin the first direction X.

The first bank 170 may include a hydrophilic material to have ahydrophilic property. The second bank 172 may include a first pattern(not shown) including a hydrophilic material and a second pattern (notshown) including a hydrophobic material and positioned on the firstpattern. In this instance, the first pattern may include the samematerial as the first bank 170 and may extend from the first bank 170.The second bank 172 may include the second pattern without the firstpattern.

A first partition wall (or a pixel dividing pattern) 182 being across apixel column of the second pixel P2 is disposed in the second pixel P2along the second direction Y. Namely, the second pixel P2 is dividedinto two regions by the first partition wall 182.

In addition, a second partition wall 184 being across a pixel column ofthe third pixels P3 is disposed in the third pixel P3 along the seconddirection Y. Namely, the third pixel P3 is divided into two regions bythe second partition wall 184.

The second bank 172 may have a fourth width W4, and each of the firstand second partition walls 182 and 184 may have a fifth width W5 equalto or smaller than the fourth width W4. Since the first and secondpartition walls 182 and 184 are located in an emission region, the widthof the first and second partition walls 182 and 184 can be reduced toreduce the decrease of the emission area. In FIG. 2, the first andsecond partition walls 182 and 184 have the same width. Alternatively,the width of the second partition wall 184 formed in the third pixel P3having the third width W3 smaller than the second width W2 of the secondpixel P2 may be smaller than that of the first partition wall 182 suchthat it is possible to make the widths of the regions, where the lightemitting layer in the second and third pixels P2 and P3 is formed,substantially the same. For example, by adjusting the widths of thefirst and second partition walls 182 and 184, the first width W1 of thefirst pixel P1, a width W2′ of the divided region of the second pixelP2, and a width of the divided region of the third pixel P3 can besubstantially equal.

In the EL display device of the present disclosure, the light emittingdiode including the light emitting layer are formed in each of thepixels P1, P2, and P3, and the light emitting layer is formed by asolution process. Namely, the light emitting layer can be formed by asolution process without a mask such that the manufacturing cost of theEL display device is reduced and the EL display device having a largesize and high resolution can be provided.

In addition, since the light emitting layers having the same color areintegrally formed to be connected to each other, variations (ordeviations) in the dropping amount of nozzles can be reduced, and athickness of the light emitting layer in each pixel can be uniform.

However, in each pixel column in which the pixels P1, P2, and P3 of thesame color are arranged along the second direction Y, a solution isshifted from the end of the pixel column to the center of the pixelcolumn. Accordingly, a region, in which the light emitting layer is notformed, is generated in a pixel at the end of the pixel column, or athickness nonuniformity problem of the light emitting layer occurs.

When a width of the pixel column is relatively small, the solution shiftproblem is not generated or reduced. On the other hand, when a width ofthe pixel column is relatively large, the solution shift problem issignificantly generated.

Namely, the solution shift problem may be greater in the second pixel P2as the blue pixel and/or the third pixel P3 as the green pixel, each ofwhich has a width being greater than the first pixel P1 as the redpixel, than the first pixel P1.

However, in the EL display device of the present disclosure, the firstpartition wall 182 extending along the second direction Y is formed inthe second pixel P2, which has relatively large width in the firstdirection X, such that the second pixel P2 is divided into two regionshaving reduced width. Accordingly, each region in the second pixel X2has relatively small width such that the solution shift problem in thesecond pixel P2 is prevented or minimized.

In addition, the second partition wall 184 extending along the seconddirection Y is formed in the third pixel P3 such that the third pixel P3is divided into two regions having reduced width. Accordingly, eachregion in the third pixel P3 has relatively small width such that thesolution shift problem in the third pixel P3 is prevented or minimized.

In FIG. 2, the first and second partition walls 182 and 184 arerespectively disposed in the second and third pixels P2 and P3.Alternatively, the second partition wall 184 formed in the third pixelP3, which has a width being smaller than the second pixel P2, may beomitted.

FIG. 3 is a cross-sectional view taken along the line I-I′ of FIG. 2,and FIG. 4 is a cross-sectional view taken along the line II′-II′ ofFIG. 2.

Referring to FIGS. 3 and 4 with FIG. 2, on a substrate 110, where thefirst to third pixels P1, P2, and P3 are defined, the TFT Tr, the lightemitting diode D, which is connected to the TFT Tr, the first bank 170,which is formed at the boundary of the adjacent pixel along the firstdirection X, the second bank 172, which is formed at the boundary of theadjacent pixel along the second direction Y, the first partition wall182 being across the second pixel P2 along the second direction Y, andthe second partition wall 184 being across the third pixel P3 along thesecond direction Y are formed.

The substrate 110 may be a glass substrate or a plastic substrate. Forexample, the substrate 110 may be a polyimide substrate.

A buffer layer 120 is formed on the substrate 110, and the TFT Tr isformed on the buffer layer 120. The buffer layer 120 may include aninorganic material, e.g., silicon oxide or silicon nitride, and may havea single-layered structure or a double-layered structure. The bufferlayer 120 may be omitted.

A semiconductor layer 122 is formed on the buffer layer 120. Thesemiconductor layer 122 may include an oxide semiconductor material orpolycrystalline silicon.

When the semiconductor layer 122 includes the oxide semiconductormaterial, a light-shielding pattern (not shown) may be formed under thesemiconductor layer 122. The light to the semiconductor layer 122 isshielded or blocked by the light-shielding pattern such that thermaldegradation of the semiconductor layer 122 can be prevented. On theother hand, when the semiconductor layer 122 includes polycrystallinesilicon, impurities may be doped into both sides of the semiconductorlayer 122.

A gate insulating layer 124 is formed on the semiconductor layer 122.The gate insulating layer 124 may be formed of an inorganic insulatingmaterial such as silicon oxide or silicon nitride.

A gate electrode 130 and a gate line GL, each of which is formed of aconductive material, e.g., metal, is formed on the gate insulating layer124. The gate electrode 130 corresponds to a center of the semiconductorlayer 122. The gate line GL extends along the first direction X. Thegate line GL may overlap the first bank 170.

In FIG. 3, the gate insulating layer 124 is formed on an entire surfaceof the substrate 110. Alternatively, the gate insulating layer 124 maybe patterned to have the same shape as the gate electrode 130.

An interlayer insulating layer 132, which is formed of an insulatingmaterial, is formed on the gate electrode 130. The interlayer insulatinglayer 132 may be formed of an inorganic insulating material, e.g.,silicon oxide or silicon nitride, or an organic insulating material,e.g., benzocyclobutene or photo-acryl.

The interlayer insulating layer 132 includes first and second contactholes 134 and 136 exposing both sides of the semiconductor layer 122.The first and second contact holes 134 and 136 are positioned at bothsides of the gate electrode 130 to be spaced apart from the gateelectrode 130.

In FIG. 3, the first and second contact holes 134 and 136 are formedthrough the gate insulating layer 124. Alternatively, when the gateinsulating layer 124 is patterned to have the same shape as the gateelectrode 130, the first and second contact holes 134 and 136 is formedonly through the interlayer insulating layer 132.

A source electrode 142, a drain electrode 140 and a data line DL, eachof which is formed of a conductive material, e.g., metal, are formed onthe interlayer insulating layer 132.

The source electrode 142 and the drain electrode 140 are spaced apartfrom each other with respect to the gate electrode 130 and respectivelycontact both sides of the semiconductor layer 122 through the first andsecond contact holes 134 and 136. The data line DL extends along thesecond direction Y. The data line DL crosses the gate line GL to definethe pixels P1, P2 and P3. The data line DL may overlap the second bank172.

The semiconductor layer 122, the gate electrode 130, the sourceelectrode 142 and the drain electrode 140 constitute the TFT Tr. The TFTTr may serve as a driving element. Namely, the TFT Tr may be the drivingTFT Td.

In the TFT Tr, the gate electrode 130, the source electrode 142, and thedrain electrode 140 are positioned over the semiconductor layer 122.Namely, the TFT Tr has a coplanar structure.

Alternatively, in the TFT Tr, the gate electrode may be positioned underthe semiconductor layer, and the source and drain electrodes may bepositioned over the semiconductor layer such that the TFT Tr may have aninverted staggered structure. In this instance, the semiconductor layermay include amorphous silicon.

Although not shown, the switching TFT Ts (of FIG. 1) may be furtherformed on the substrate 110. The switching TFT Ts is connected to theTFT Tr as the driving TFT.

In addition, the power line PL (of FIG. 1) is formed to be parallel toand spaced apart from the data line DL or the gate line GL. The storagecapacitor Cst (of FIG. 1) for maintaining the voltage of the gateelectrode of the TFT Tr as the driving TFT is further formed.

A passivation layer (or planarization layer) 150 including a draincontact hole 152, which exposes the drain electrode 140 of the TFT Tr,is formed to cover the TFT Tr.

A first electrode 160 is formed on the passivation layer 150 and isconnected to the drain electrode 142 of the TFT Tr through the draincontact hole 152. The first electrode 160 is separated in each of thefirst to third pixels P1, P2 and P3. The first electrode 160 may beformed of a conductive material having a relatively high work functionto serve as an anode. For example, the first electrode 160 may be formedof a transparent conductive material such as indium-tin-oxide (ITO) orindium-zinc-oxide (IZO), but it is not limited thereto.

When the EL display device 100 is operated in a top-emission type, areflection electrode or a reflection layer may be formed under the firstelectrode 160. For example, the reflection electrode or the reflectionlayer may be formed of silver (Ag) or aluminum-palladium-copper (APC)alloy. The first electrode 160 may have a triple-layered structure ofITO/APC/ITO or ITO/Ag/ITO, but it is not limited thereto.

The first and second banks 170 and 172 covering edges of the firstelectrode 160 are formed on the passivation layer 150. The first andsecond banks 170 and 172 exposes a center of the first electrode 160 inthe first to third pixels P1, P2 and P3. The first bank 170 has athickness (or height) being smaller than the second bank 172. The secondbank 172 may include first and second patterns 174 and 176 sequentiallystacked.

In the pixel column of the second pixel P2, the first partition wall 182being across (running across) the second pixel P2 along the seconddirection Y is formed. In addition, in the pixel column of the thirdpixel P3, the second partition wall 184 being across (running across)the third pixel P3 along the second direction Y is formed.

Each of the first and second partition walls 182 and 184 may be formedof the same material as the second pattern 176 of the second bank 172.Namely, each of the first and second partition walls 182 and 184 may beformed of a hydrophobic material to have a hydrophobic property.Alternatively, each of the first and second partition walls 182 and 184may be formed of a hydrophilic material to have a hydrophilic property.

In addition, each of the first and second partition walls 182 and 184may have a double-layered structure of a lower pattern and an upperpattern. The lower and the upper pattern may be formed of the samematerial as the first and second patterns 174 and 176 of the second bank172, respectively.

Moreover, the first bank 170, the second bank 172, the first partitionwall 182 and the second partition wall 184 may be formed of the sameprocess. For example, by forming an organic material layer having ahydrophobic top surface over an entire surface of the substrate 110 andpatterning the organic material layer using a half-tone mask, whichincludes a transmissive area, a blocking area and a half-transmissivearea, the first bank 170, the second bank 172, the first partition wall182 and the second partition wall 184 having different widths anddifferent thicknesses may be formed.

The second bank 172 has a first height H1 from the substrate 110, andthe first partition wall 182 has a second height H2 from the substrate110. The second height H2 may be equal to or smaller than the firstheight H1.

The second bank 172 should have a predetermined height to prevent colormixing between adjacent pixels of different colors. However, since thelight emitting layers of the same color are coated on both sides of thefirst partition wall 182, the first partition wall 182 may have a heightbeing smaller than the bank 172. In addition, the second partition wall184 may have substantially the same height as the first partition wall182.

For example, the second pixel P2 is divided by the first partition wall182, but the first electrode 160 in two regions divided by the firstpartition wall 182 is connected to one TFT Tr. Namely, the two regionsseparated by the first partition wall 182 constitute the second pixelP2.

A light emitting layer 162 is formed on the first electrode 160 of eachpixel P1, P2, P3. For example, the light emitting layer 162 may includea first charge auxiliary layer, an emitting material layer, and a secondcharge auxiliary layer sequentially stacked on the first electrode 160.The light emitting material layer 162 is formed by coating red, blue,and green emitting materials on the first to third pixels P1, P2, andP3. The emitting material may be an organic emitting material, such as aphosphorescent compound or a fluorescent compound, or an inorganicemitting material such as a quantum dot.

The first charge auxiliary layer may be a hole auxiliary layer, and thehole auxiliary layer may include at least one of a hole injection layer(HIL) and a hole transporting layer (HTL). The second charge auxiliarylayer may be an electron auxiliary layer, and the electron auxiliarylayer may include at least one of an electron injection layer (EIL) andan electron transporting layer (ETL). However, the present disclosure isnot limited thereto.

The light emitting layer 162 is formed through a solution process.Accordingly, the process can be simplified, and a large-size andhigh-resolution display device can be provided. For example, thesolution process may be a spin-coating method, an inkjet-printingmethod, or a screen-printing method, but it is not limited thereto.

For example, an emitting material solution is coated to a pixel columnof the first pixels P1 and dried to form the light emitting layer 162 inthe plurality of first pixels P1 arranged in the second direction Y. Inthis case, the light emitting layers 162 of the first pixels P1 adjacentin the second direction Y are connected to each other and are formed tocover the first bank 170.

An emitting material solution is coated to a pixel column of the secondpixels P2 and dried to form the light emitting layer 162 in theplurality of second pixels P2 arranged in the second direction Y. Inthis case, the light emitting layers 162 of the second pixels P2adjacent in the second direction Y are connected to each other and areformed to cover the first bank 170. Since the first partition wall 182being across the second pixel P2 is formed along the second direction Y,the light emitting layer 162 in the second pixel P2 is divided by thefirst partition wall 182. Namely, in the pixel column of the secondpixel P2, the emitting layer 162 is continuous in adjacent second pixelsP2 and is separated (or divided) in one second pixel P2.

As mentioned above, when the light emitting layer 162 is formed by asolution process, a solution shift problem in the second direction Y isgenerated in the second pixel P2, which has a width being greater thanthe first pixel P1. However, in the EL display device of the presentdisclosure, the second pixel P2 is divided by the first partition wall182 such that a width of the region, where the emitting materialsolution is coated, is reduced. Accordingly, the solution shift problemin the second pixel P2 is prevented or reduced.

An emitting material solution is coated to a pixel column of the thirdpixels P3 and dried to form the light emitting layer 162 in theplurality of third pixels P3 arranged in the second direction Y. In thiscase, the light emitting layers 162 of the third pixels P3 adjacent inthe second direction Y are connected to each other and are formed tocover the first bank 170. Since the second partition wall 184 beingacross the third pixel P2 is formed along the second direction Y, thelight emitting layer 162 in the third pixel P3 is divided by the secondpartition wall 184. Namely, in the pixel column of the third pixel P3,the emitting layer 162 is continuous in adjacent third pixels P3 and isseparated (or divided) in one third pixel P3.

Since the third pixel P3 is divided by the second partition wall 184,the solution shift problem in the third pixel P3 is prevented orreduced.

Accordingly, problems in that the light emitting layer is not formed ora thickness of the light emitting layer is non-uniform in a part of thepixel of the pixel column of the second pixel P2 or the third pixel P3can be prevented.

The first partition wall 182 in the second pixel P2 and the secondpartition wall 184 in the third pixel P3 may correspond to the TFT Trand/or the drain contact hole 152. Namely, the first partition wall 182in the second pixel P2 and the second partition wall 184 in the thirdpixel P3 may overlap the TFT Tr and/or the drain contact hole 152.

For example, a step difference in the first electrode 160 may begenerated by the drain contact hole 152 such that a thicknessnon-uniformity problem in the light emitting layer 162 may be generated.However, when the first and second partition walls 182 and 184 areformed to correspond to the drain contact hole 152, the above problemcan be prevented.

On the other hand, the electron auxiliary layer of the light emittinglayer 162 may be formed by a deposition process. In this instance, theelectron auxiliary layer may be substantially formed over an entire ofthe substrate 110.

A second electrode 164 is formed on the light emitting layer 162, thesecond bank 172, and the first and second partition walls 182 and 184and over an entire of the substrate 110. The second electrode 164 may beformed of a conductive material having a relatively low work function toserve as a cathode. For example, the second electrode 164 may be formedof aluminum (Al), magnesium (Mg), silver (Ag) or their alloy.Alternatively, the second electrode 164 may be formed of a transparentconductive material such as indium-gallium-oxide (IGO), but it is notlimited thereto. As mentioned above, the EL display device 100 of thepresent disclosure may be a top-emission type. As a result, the secondelectrode 164 has relatively small thickness in order to transmit thelight from the light emitting layer 162.

The first electrode 160, the light emitting layer 162 and the secondelectrode 164 constitute the light emitting diode D.

Although not shown, an encapsulation film may be formed on or over thesecond electrode 164 to prevent penetration of moisture into the lightemitting diode D. The encapsulation film may have a triple-layeredstructure of a first inorganic layer, an organic layer and a secondinorganic layer, but it is not limited thereto.

In addition, a polarization plate may be disposed on the encapsulationfilm to reduce an ambient light reflection. The polarization plate maybe a circular polarization film.

Moreover, a cover window may be attached to the encapsulation film orthe polarization plate. For example, the substrate 110 and the coverwindow may have a flexible property such that a flexible EL displaydevice may be provided.

FIG. 5 is a schematic plan view of a part of an EL display deviceaccording to a second embodiment of the present disclosure.

As shown in FIG. 5, the EL display device 200 according to the secondembodiment of the present disclosure includes first to third pixels P1,P2 and P3. The different color pixels are arranged along a firstdirection X, and the same color pixels are arranged along a seconddirection Y. Namely, the first to third pixels P1 to P3, which aredifferent from each other, are sequentially arranged along the firstdirection X, and the first pixels P1, the second pixels P2 and the thirdpixels P3 are respectively arranged along the second direction Y. Forexample, the first pixel P1 may be a red pixel, the second pixel P2 maybe a blue pixel, and the third pixel P3 may be a green pixel. The lightemitting diode D is disposed in each pixel P1, P2 and P3.

The first to third pixels P1, P2 and P3 respectively have first to thirdwidths W1, W2 and W3. The third width W3 is greater than the first widthW1 and smaller than the second width W2.

A first bank 270 is disposed in a portion between adjacent same colorpixels arranged along the second direction Y. The first bank 270 isdisposed between adjacent first pixels P1, between adjacent secondpixels P2, and between adjacent third pixels P3. Namely, the first pixel270 extends between same pixels, which are adjacent along the seconddirection Y, along the first direction X. Alternatively, the first bank270 may be omitted.

A second bank 272 is disposed in a portion between adjacent two pixelamong the first to third pixels P1 to P3 in the first direction X. Thesecond bank 272 is disposed between the first and second pixels P1 andP2, between the second and third pixels P2 and P3, and between the thirdand first pixels P3 and P1. Namely, the second bank 272 extends betweendifferent pixels, which are adjacent along the first direction X, alongthe second direction Y. The second bank 272 has an opening incorrespondence to the same color pixels arranged along the seconddirection Y. The second bank 272 has a single opening in correspondenceto all of the first pixels P1, all of the second pixels P2 or all of thethird pixels P3 in one pixel column. Namely, the opening of the secondbank 272 extends along the second direction Y, and a length of theopening in the second direction Y is larger than a length of the openingin the first direction X.

The first bank 270 may include a hydrophilic material to have ahydrophilic property. The second bank 272 may include a first pattern(not shown) including a hydrophilic material and a second pattern (notshown) including a hydrophobic material and positioned on the firstpattern. In this instance, the first pattern may include the samematerial as the first bank 270 and may extend from the first bank 270.The second bank 272 may include the second pattern without the firstpattern.

A first partition wall 282 being across a pixel column of the secondpixels P2 is disposed along the second direction Y. Namely, the secondpixel P2 is divided into two regions by the first partition wall 282.

In at least one end of the pixel column of the second pixels P2, thefirst partition wall 282 is spaced apart from the second bank 272 by afirst distance d1. Namely, in at least one end of the pixel column ofthe second pixels P2, there is a space between the first partition wall282 and the second bank 272. In the second direction Y, a length of thespace between the first partition wall 282 and the second bank 272 issmaller than a length of the second pixel P2. Namely, an end of thefirst partition wall 282 is disposed in the second pixel P2 at the endof the pixel column of the second pixels P2.

In addition, a second partition wall 284 being across a pixel column ofthe third pixels P3 is disposed along the second direction Y. Namely,the third pixel P3 is divided into two regions by the second partitionwall 284.

In at least one end of the pixel column of the third pixels P3, thesecond partition wall 284 is spaced apart from the second bank 272 by asecond distance d2. Namely, in at least one end of the pixel column ofthe third pixels P3, there is a space between the second partition wall284 and the second bank 272. In the second direction Y, a length of thespace between the second partition wall 284 and the second bank 272 issmaller than a length of the third pixel P3. Namely, an end of thesecond partition wall 284 is disposed in the third pixel P3 at the endof the pixel column of the third pixels P3.

The first distance d1 between the first partition wall 282 and thesecond bank 272 may be equal to or larger than the second distance d2between the second partition wall 284 and the second bank 272.

The second bank 272 may have a fourth width W4, and each of the firstand second partition walls 282 and 284 may have a fifth width W5 equalto or smaller than the fourth width W4. A width of the second partitionwall 282 in the third pixel P3 may be equal to or smaller than a widthof the first partition wall 282 in the second pixel P2.

In FIG. 5, the first and second partition walls 282 and 284 arerespectively disposed in the second and third pixels P2 and P3.Alternatively, the second partition wall 284 in the third pixel P3,which has a width being smaller than the second pixel P2, may beomitted.

In the EL display device of the present disclosure, the light emittingdiode including the light emitting layer are formed in each of thepixels P1, P2, and P3, and the light emitting layer is formed by asolution process. Namely, the light emitting layer can be formed by asolution process without a mask such that the manufacturing cost of theEL display device is reduced and the EL display device having a largesize and high resolution can be provided.

In addition, since the light emitting layers having the same color areintegrally formed to be connected to each other, variations (ordeviations) in the dropping amount of nozzles can be reduced, and athickness of the light emitting layer in each pixel can be uniform.

Moreover, since the first and second partition walls 282 and 284 arerespectively formed in the second and third pixels P2 and P3, each ofwhich has a width in the first direction X being larger than the firstpixel P1, the solution shift problem in the second and third pixels P2and P3 is prevented or reduced.

Furthermore, since the first partition wall 282 is spaced apart from thesecond bank 272 in at least one end of the pixel column of the secondpixels P2, a flow path of the fluid, i.e., an emitting materialsolution, is provided in the pixel column of the second pixels P2. As aresult, the thickness uniformity of the organic emitting layer in thesecond pixel P2 is further improved. Similarly, since the secondpartition wall 284 is spaced apart from the second bank 272 in at leastone end of the pixel column of the third pixels P3, a flow path of thefluid, i.e., an emitting material solution, is provided in the pixelcolumn of the third pixels P3. As a result, the thickness uniformity ofthe organic emitting layer in the third pixel P3 is further improved.

FIG. 6 is a schematic plan view of a part of an EL display deviceaccording to a third embodiment of the present disclosure.

As shown in FIG. 6, the EL display device 300 according to the secondembodiment of the present disclosure includes first to third pixels P1,P2 and P3 and first to third dummy pixels DP1, DP2, DP3. The differentcolor pixels are arranged along a first direction X, and the same colorpixels are arranged along a second direction Y to form first to thirdpixel columns. The first to third dummy pixels DP1, DP2 and DP3 arerespectively positioned at both ends of the first to third pixelcolumns, respectively.

For example, the first pixel P1 may be a red pixel, the second pixel P2may be a blue pixel, and the third pixel P3 may be a green pixel. Thelight emitting diode D is disposed in each pixel P1, P2 and P3.

The first to third pixels P1, P2 and P3 respectively have first to thirdwidths W1, W2 and W3. The third width W3 is greater than the first widthW1 and smaller than the second width W2.

A first bank 370 is disposed in a portion between adjacent same colorpixels arranged along the second direction Y and between each of thedummy pixels DP1, DP2 and DP3 and each of the pixels P1, P2 and P3. Thefirst bank 370 is disposed between adjacent first pixels P1, betweenadjacent second pixels P2, between adjacent third pixels P3, between thefirst dummy pixel DP1 and the first pixel P1, between the second dummypixel DP2 and the second pixel P2, and between the third dummy pixel DP3and the third pixel P3. Namely, the first bank 370 extends between samecolor pixels, which are adjacent along the second direction Y, along thefirst direction X and between each dummy pixel DP1, DP2 and DP3 and eachpixel P1, P2 and P3, which are adjacent along the second direction Y,along the first direction X. Alternatively, the first bank 370 may beomitted.

A second bank 372 is disposed in a portion between adjacent two pixelsamong the first to third pixels P1 to P3 in the first direction X and aportion between adjacent two pixels among the first to third dummypixels DP1 to DP3. The second bank 372 is disposed between the first andsecond pixels P1 and P2, between the second and third pixels P2 and P3,between the third and first pixels P3 and P1, between the first andsecond dummy pixels DP1 and DP2, between the second and third dummypixels DP2 and DP3, and between the third and first dummy pixels DP3 andDP1. Namely, the second bank 372 extends between different pixels, whichare adjacent along the first direction X, along the second direction Yand between the dummy pixels DP1 to DP3, which are adjacent along thefirst direction X, along the second direction Y. The second bank 372 hasan opening in correspondence to the same color pixels and the dummypixel arranged along the second direction Y. The second bank 372 has asingle opening in correspondence to all of the first pixels P1 and thefirst dummy pixel DP1 in the first pixel column, all of the secondpixels P2 and the second dummy pixel DP2 in the second pixel column, orall of the third pixels P3 and the third dummy pixel DP3 in the thirdpixel column. Namely, the opening of the second bank 372 extends alongthe second direction Y, and a length of the opening in the seconddirection Y is larger than a length of the opening in the firstdirection X.

The first bank 370 may include a hydrophilic material to have ahydrophilic property. The second bank 372 may include a first pattern(not shown) including a hydrophilic material and a second pattern (notshown) including a hydrophobic material and positioned on the firstpattern. In this instance, the first pattern may include the samematerial as the first bank 370 and may extend from the first bank 370.The second bank 372 may include the second pattern without the firstpattern.

A first partition wall 382 being across the second pixel column of thesecond pixels P2 is disposed along the second direction Y. Namely, thesecond pixel P2 is divided into two regions by the first partition wall382.

In at least one end of the second pixel column of the second pixels P2,the first partition wall 382 is spaced apart from the second bank 372 bya length of the second dummy pixel DP2. Namely, in at least one end ofthe second pixel column of the second pixels P2, there is a space havingthe length of the second dummy pixel DP2 between the first partitionwall 382 and the second bank 372.

In addition, a second partition wall 384 being across the third pixelcolumn of the third pixels P3 is disposed along the second direction Y.Namely, the third pixel P3 is divided into two regions by the secondpartition wall 384.

In at least one end of the third pixel column of the third pixels P3,the second partition wall 384 is spaced apart from the second bank 372by a length of the third dummy pixel DP3. Namely, in at least one end ofthe third pixel column of the third pixels P3, there is a space havingthe length of the third dummy pixel DP3 between the second partitionwall 384 and the second bank 372.

Alternatively, the first and second partition walls 382 and 384 mayrespectively extend from the second bank 372 to be across the second andthird dummy pixels DP2 and DP3. Namely, the second and third dummypixels DP2 and DP3 may be divided by the first and second partitionwalls 382 and 384, respectively.

Alternatively, the first and second partition walls 382 and 384 mayextend into a portion of the second and third dummy pixels DP2 and DP3,respectively. In this instance, a first distance between the firstpartition wall 382 and the second bank 372 may be equal to or greaterthan a second distance between the second partition wall 384 and thesecond bank 372.

The second bank 372 may have a fourth width W4, and each of the firstand second partition walls 382 and 384 may have a fifth width W5 equalto or smaller than the fourth width W4. A width of the second partitionwall 384 in the third pixel P3 may be equal to or smaller than a widthof the first partition wall 382 in the second pixel P2.

In FIG. 6, the first and second partition walls 382 and 384 arerespectively disposed in the second and third pixels P2 and P3.Alternatively, the second partition wall 384 in the third pixel P3,which has a width being smaller than the second pixel P2, may beomitted.

FIG. 7 is a cross-sectional view taken along the line of FIG. 6.

Referring to FIG. 7 with FIGS. 3 and 6, on a substrate 310, where thefirst to third pixels P1 to P3 and the first to third dummy pixels DP1to DP3 are defined, the TFT Tr, the light emitting diode D, which isconnected to the TFT Tr, the first bank 370, which is formed at theboundary of the adjacent pixel along the first direction X, the secondbank 372, which is formed at the boundary of the adjacent pixel alongthe second direction Y, the first partition wall 382 being across thesecond pixel P2 along the second direction Y, and the second partitionwall 384 being across the third pixel P3 along the second direction Yare formed.

The substrate 310 may be a glass substrate or a plastic substrate. Forexample, the substrate 310 may be a polyimide substrate.

The buffer layer 320 is formed on the substrate 310, and thesemiconductor layer is formed on the buffer layer 320. The semiconductorlayer may include an oxide semiconductor material or polycrystallinesilicon.

The gate insulating layer is formed on the semiconductor layer, and thegate electrode and the gate line, each of which is formed of aconductive material, e.g., metal, is formed on the gate insulatinglayer. The gate electrode corresponds to a center of the semiconductorlayer, and the gate line extends along the first direction X. The gateline may overlap the first bank 370.

The interlayer insulating layer, which is formed of an insulatingmaterial and includes the first and second contact holes exposing bothsides of the semiconductor layer, is formed on the gate electrode.

The source electrode, the drain electrode and the data line, each ofwhich is formed of a conductive material, e.g., metal, are formed on theinterlayer insulating layer.

The source electrode and the drain electrode are spaced apart from eachother with respect to the gate electrode and respectively contact bothsides of the semiconductor layer through the first and second contactholes. The data line extends along the second direction Y. The data linemay overlap the second bank 372.

The semiconductor layer, the gate electrode, the source electrode andthe drain electrode constitute the TFT Tr. The TFT Tr may be formed ineach of the first to third pixels P1 to P3 and the first to third dummypixels DP1 to DP3.

A passivation layer (or planarization layer) 350, which includes a draincontact hole 352 exposing the drain electrode of the TFT Tr in the firstto third pixels P1 to P3, is formed to cover the TFT Tr. The passivationlayer 350 in the first to third dummy pixels DP1 to DP3 completelycovers the TFT Tr without a drain contact hole.

The first electrode 360, which is separated in each of the first tothird pixels P1 to P3 and each of the first to third dummy pixels DP1 toDP3, is formed on the passivation layer 350. The first electrode 360 inthe first to third pixels P1 to P3 is connected to the drain electrodeof the TFT Tr through the drain contact hole 352. The first electrode360 in the first to third dummy pixels DP1 to DP3 is electricallyfloated.

The first electrode 360 may be formed of a conductive material having arelatively high work function to serve as an anode. For example, thefirst electrode 360 may be formed of a transparent conductive materialsuch as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO), but it is notlimited thereto.

When the EL display device 300 is operated in a top-emission type, areflection electrode or a reflection layer may be formed under the firstelectrode 360. For example, the reflection electrode or the reflectionlayer may be formed of silver (Ag) or aluminum-palladium-copper (APC)alloy. The first electrode 360 may have a triple-layered structure ofITO/APC/ITO or ITO/Ag/ITO, but it is not limited thereto.

The first and second banks 370 and 372 covering edges of the firstelectrode 360 are formed on the passivation layer 350. The first andsecond banks 370 and 372 exposes a center of the first electrode 360 inthe first to third pixels P1 to P3 and the first to third dummy pixelsDP1 to DP3. The first bank 370 has a thickness (or height) being smallerthan the second bank 372. The second bank 372 may include first andsecond patterns 374 and 376 sequentially stacked.

In the second pixel column of the second pixels P2 and the second dummypixels DP2, the first partition wall 382 being across (running across)the second pixel P2 along the second direction Y is formed. In addition,in the third pixel column of the third pixels P3 and the third dummypixels DP3, the second partition wall 384 being across (running across)the third pixel P3 along the second direction Y is formed.

Each of the first and second partition walls 382 and 384 may be formedof the same material as the second pattern 376 of the second bank 372.Namely, each of the first and second partition walls 382 and 384 may beformed of a hydrophobic material to have a hydrophobic property.Alternatively, each of the first and second partition walls 382 and 384may be formed of a hydrophilic material to have a hydrophilic property.

In addition, each of the first and second partition walls 382 and 384may have a double-layered structure of a lower pattern and an upperpattern. The lower and the upper pattern may be formed of the samematerial as the first and second patterns 374 and 376 of the second bank372, respectively.

Moreover, the first bank 370, the second bank 372, the first partitionwall 382 and the second partition wall 384 may be formed of the sameprocess. For example, by forming an organic material layer having ahydrophobic top surface over an entire surface of the substrate 310 andpatterning the organic material layer using a half-tone mask, whichincludes a transmissive area, a blocking area and a half-transmissivearea, the first bank 370, the second bank 372, the first partition wall382 and the second partition wall 384 having different widths anddifferent thicknesses may be formed.

The second bank 372 has a first height H1 from the substrate 310, andthe first partition wall 382 has a second height H2 from the substrate310. The second height H2 may be equal to or smaller than the firstheight H1.

The second bank 372 should have a predetermined height to reduce colormixing between adjacent pixels of different colors. However, since thelight emitting layers of the same color are coated on both sides of thefirst partition wall 382, the first partition wall 382 may have a heightbeing smaller than the second bank 372. In addition, the secondpartition wall 384 may have substantially the same height as the firstpartition wall 382.

For example, the second pixel P2 is divided by the first partition wall382, but the first electrode 360 in two regions divided by the firstpartition wall 382 is connected to one TFT Tr. Namely, the two regionsseparated by the first partition wall 382 constitute the second pixelP2.

The first and second partition walls 382 and 384 does not present in thesecond and third dummy pixels DP2 and DP3, respectively, and are spacedapart from the second bank 372. Alternatively, the first and secondpartition walls 382 and 384 may be connected to the second bank 372 tobe across the second and third dummy pixels DP2 and DP3, respectively,or the first and second partition walls 382 and 384 may extend into apart of the second and third dummy pixels DP2 and DP3, respectively.

The light emitting layer 362 is formed on the first electrode 360 ofeach pixel P1, P2, P3. For example, the light emitting layer 362 mayinclude a first charge auxiliary layer, an emitting material layer, anda second charge auxiliary layer sequentially stacked on the firstelectrode 360. The light emitting material layer 362 is formed bycoating red, blue, and green emitting materials on the first to thirdpixels P1 to P3. The emitting material may be an organic emittingmaterial, such as a phosphorescent compound or a fluorescent compound,or an inorganic emitting material such as a quantum dot.

The first charge auxiliary layer may be a hole auxiliary layer, and thehole auxiliary layer may include at least one of a hole injection layer(HIL) and a hole transporting layer (HTL). The second charge auxiliarylayer may be an electron auxiliary layer, and the electron auxiliarylayer may include at least one of an electron injection layer (EIL) andan electron transporting layer (ETL). However, the present disclosure isnot limited thereto.

The light emitting layer 362 is formed through a solution process.Accordingly, the process can be simplified, and a large-size andhigh-resolution display device can be provided. For example, thesolution process may be a spin-coating method, an inkjet-printingmethod, or a screen-printing method, but it is not limited thereto.

For example, an emitting material solution is coated to a pixel columnof the first pixels P1 and dried to form the light emitting layer 362 inthe plurality of first pixels P1 arranged in the second direction Y. Inthis case, the light emitting layers 362 of the first pixels P1 adjacentin the second direction Y are connected to each other and are formed tocover the first bank 370.

An emitting material solution is coated to a pixel column of the secondpixels P2 and dried to form the light emitting layer 362 in theplurality of second pixels P2 arranged in the second direction Y. Inthis case, since the first partition wall 382 being across the secondpixel P2 is formed along the second direction Y, the light emittinglayer 362 in the second pixel P2 is divided by the first partition wall382.

An emitting material solution is coated to a pixel column of the thirdpixels P3 and dried to form the light emitting layer 362 in theplurality of third pixels P3 arranged in the second direction Y. In thiscase, since the second partition wall 384 being across the third pixelP3 is formed along the second direction Y, the light emitting layer 362in the third pixel P3 is divided by the second partition wall 384.

The first partition wall 382 in the second pixel P2 and the secondpartition wall 384 in the third pixel P3 may correspond to the TFT Trand/or the drain contact hole 352. Namely, the first partition wall 382in the second pixel P2 and the second partition wall 384 in the thirdpixel P3 may overlap the TFT Tr and/or the drain contact hole 352.

The second electrode 364 is formed on the light emitting layer 362, thesecond bank 372, and the first and second partition walls 382 and 384and over an entire of the substrate 310. The second electrode 364 may beformed of a conductive material having a relatively low work function toserve as a cathode. For example, the second electrode 364 may be formedof aluminum (Al), magnesium (Mg), silver (Ag) or their alloy.Alternatively, the second electrode 364 may be formed of a transparentconductive material such as indium-gallium-oxide (IGO), but it is notlimited thereto. As mentioned above, the EL display device 300 of thepresent disclosure may be a top-emission type. As a result, the secondelectrode 364 has relatively small thickness in order to transmit thelight from the light emitting layer 362.

The first electrode 360, the light emitting layer 362 and the secondelectrode 364 constitute the light emitting diode D.

Although not shown, an encapsulation film may be formed on or over thesecond electrode 364 to prevent penetration of moisture into the lightemitting diode D. The encapsulation film may have a triple-layeredstructure of a first inorganic layer, an organic layer and a secondinorganic layer, but it is not limited thereto.

In addition, a polarization plate may be disposed on the encapsulationfilm to reduce an ambient light reflection. The polarization plate maybe a circular polarization film.

Moreover, a cover window may be attached to the encapsulation film orthe polarization plate. For example, the substrate 310 and the coverwindow may have a flexible property such that a flexible EL displaydevice may be provided.

In the EL display device of the present disclosure, the light emittingdiode including the light emitting layer are formed in each of thepixels P1, P2, and P3, and the light emitting layer is formed by asolution process. Namely, the light emitting layer can be formed by asolution process without a mask such that the manufacturing cost of theEL display device is reduced and the EL display device having a largesize and high resolution can be provided.

In addition, since the light emitting layers having the same color areintegrally formed to be connected to each other, variations (ordeviations) in the dropping amount of nozzles can be reduced, and athickness of the light emitting layer in each pixel can be uniformed.

Moreover, since the first and second partition walls 382 and 384 arerespectively formed in the second and third pixels P2 and P3, each ofwhich has a width in the first direction X being larger than the firstpixel P1, the solution shift problem in the second and third pixels P2and P3 is prevented or minimized.

Furthermore, even though the light emitting layer is partially formed inthe first to third dummy pixels DP1 to DP3 at the first to third pixelcolumn by the solution shift problem, there is no problem in theemission property.

Further, since the first and second partition walls 382 and 384 arespaced apart from the second bank 272 in at least one end of the secondand third pixel columns, a flow path of the fluid, i.e., an emittingmaterial solution, is provided in the second and third pixel columns. Asa result, the thickness uniformity of the organic emitting layer in thesecond and third pixels P2 and P3 is further improved.

FIG. 8 is a schematic plan view of a part of an EL display deviceaccording to a fourth embodiment of the present disclosure.

As shown in FIG. 8, the EL display device 400 according to the fourthembodiment of the present disclosure includes first to third pixels P1to P3. The different color pixels are arranged along a first directionX, and the same color pixels are arranged along a second direction Y.Namely, the first to third pixels P1 to P3, which are different fromeach other, are sequentially arranged along the first direction X, andthe first pixels P1, the second pixels P and the third pixels P arerespectively arranged along the second direction Y. For example, thefirst pixel P1 may be a red pixel, the second pixel P2 may be a bluepixel, and the third pixel P3 may be a green pixel.

For example, the first to third pixels P1 to P3 respectively have firstto third widths W1, W2 and W3, and the third width W3 is greater thanthe first width W1 and smaller than the second width W2.

A first bank 470 is disposed in a portion between adjacent same colorpixels arranged along the second direction Y. The first bank 470 isdisposed between adjacent first pixels P1, between adjacent secondpixels P2, and between adjacent third pixels P3. Namely, the first pixel470 extends between same pixels, which are adjacent along the seconddirection Y, along the first direction X. Alternatively, the first bank470 may be omitted.

A second bank 472 is disposed in a portion between adjacent two pixelamong the first to third pixels P1 to P3 in the first direction X. Thesecond bank 472 is disposed between the first and second pixels P1 andP2, between the second and third pixels P2 and P3, and between the thirdand first pixels P3 and P1. Namely, the second bank 472 extends betweendifferent pixels, which are adjacent along the first direction X, alongthe second direction Y. The second bank 472 has an opening incorrespondence to the same color pixels arranged along the seconddirection Y. The second bank 472 has a single opening in correspondenceto all of the first pixels P1, all of the second pixels P2 or all of thethird pixels P3 in one pixel column. The opening of the second bank 472extends along the second direction Y, and a length of the opening in thesecond bank 472 in the second direction Y is larger than a length of theopening in the second bank 472 in the first direction X.

The first bank 470 may include a hydrophilic material to have ahydrophilic property. The second bank 472 may include a first pattern(not shown) including a hydrophilic material and a second pattern (notshown) including a hydrophobic material and positioned on the firstpattern. In this instance, the first pattern may include the samematerial as the first bank 470 and may extend from the first bank 470.The second bank 472 may include the second pattern without the firstpattern.

A first partition wall 482 being across a pixel column of the secondpixel P2 is disposed in the second pixel P2 along the second directionY. Namely, the second pixel P2 is divided into two regions by the firstpartition wall 482.

In addition, a second partition wall 484 being across a pixel column ofthe third pixels P3 is disposed in the third pixel P3 along the seconddirection Y. Namely, the third pixel P3 is divided into two regions bythe second partition wall 484.

The second bank 472 may have a fourth width W4, and each of the firstand second partition walls 482 and 484 may have a fifth width W5 equalto or smaller than the fourth width W4. The first partition wall 482 mayhas a width being equal to or larger than the second partition wall 484.

Each of the first and second partition walls 482 and 484 has adiscontinuous shape. Namely, the first and second partition walls 482and 484 respectively have first and second gaps G1 and G2.

The first gap G1 corresponds to a space between adjacent two secondpixels P2, and the second gap G2 corresponds to a space between adjacenttwo third pixels P3. Namely, the first gap G1 corresponds to a portionof the first bank 470 between adjacent two second pixels P2, and thesecond gap G2 corresponds to a portion of the first bank 470 betweenadjacent third pixels P3.

The first gap G1 provides a flow path of the fluid, i.e., an emittingmaterial solution, in the pixel column of the second pixels P2 such thatthe thickness uniformity of the light emitting layer of the lightemitting diode in the second pixel P2 is improved. In addition, thesecond gap G2 provides a flow path of the fluid, i.e., an emittingmaterial solution, in the pixel column of the third pixels P3 such thatthe thickness uniformity of the light emitting layer of the lightemitting diode in the third pixel P3 is improved.

In FIG. 8, the first and second partition walls 482 and 484 arerespectively disposed in the second and third pixels P2 and P3.Alternatively, the second partition wall 484 formed in the third pixelP3, which has a width being smaller than the second pixel P2, may beomitted.

In FIG. 8, the first and second partition walls 482 and 484 areconnected to the second bank 472 at an end of each of the pixel columnof the second pixels P2 and the pixel column of the third pixels P3.Alternatively, at least one of the first and second partition walls 482and 484 may be spaced apart from the second bank 472 at the end of eachof the pixel column of the second pixels P2 and the pixel column of thethird pixels P3.

In addition, a dummy pixel may be disposed at both ends of the pixelcolumn of the first pixels P1 arranged in the second direction, at bothends of the pixel column of the second pixels P2 arranged in the seconddirection, and at both ends of the pixel column of the third pixels P3arranged in the second direction.

In the EL display device of the present disclosure, the light emittingdiode including the light emitting layer are formed in each of thepixels P1, P2, and P3, and the light emitting layer is formed by asolution process. Namely, the light emitting layer can be formed by asolution process without a mask such that the manufacturing cost of theEL display device is reduced and the EL display device having a largesize and high resolution can be provided.

In addition, since the light emitting layers having the same color areintegrally formed to be connected to each other, variations (ordeviations) in the dropping amount of nozzles can be reduced, and athickness of the light emitting layer in each pixel can be uniform.

Moreover, since the first and second partition walls 482 and 484 arerespectively formed in the second and third pixels P2 and P3, each ofwhich has a width in the first direction X being larger than the firstpixel P1, the solution shift problem in the second and third pixels P2and P3 is prevented or reduced.

Furthermore, since a flow path of the fluid is provided by the first andsecond gaps G1 and G2 of the first and second partition walls 482 and484, the thickness uniformity of the light emitting layer in the secondand third pixels P2 and P3 is further improved.

FIG. 9 is a schematic plan view of a part of an EL display deviceaccording to a fifth embodiment of the present disclosure.

As shown in FIG. 9, the EL display device 400 according to the fourthembodiment of the present disclosure includes first to third pixels P1to P3. The different color pixels are arranged along a first directionX, and the same color pixels are arranged along a second direction Y.Namely, the first to third pixels P1 to P3, which are different fromeach other, are sequentially arranged along the first direction X, andthe first pixels P1, the second pixels P and the third pixels P arerespectively arranged along the second direction Y. For example, thefirst pixel P1 may be a red pixel, the second pixel P2 may be a bluepixel, and the third pixel P3 may be a green pixel.

For example, the first to third pixels P1 to P3 respectively have firstto third widths W1, W2 and W3, and the third width W3 is greater thanthe first width W1 and smaller than the second width W2.

A first bank 570 is disposed in a portion between adjacent same colorpixels arranged along the second direction Y. The first bank 570 isdisposed between adjacent first pixels P1, between adjacent secondpixels P2, and between adjacent third pixels P3. Namely, the first pixel570 extends between same pixels, which are adjacent along the seconddirection Y, along the first direction X. Alternatively, the first bank570 may be omitted.

A second bank 572 is disposed in a portion between adjacent two pixelamong the first to third pixels P1 to P3 in the first direction X. Thesecond bank 572 is disposed between the first and second pixels P1 andP2, between the second and third pixels P2 and P3, and between the thirdand first pixels P3 and P1. Namely, the second bank 572 extends betweendifferent pixels, which are adjacent along the first direction X, alongthe second direction Y. The second bank 572 has an opening incorrespondence to the same color pixels arranged along the seconddirection Y. The second bank 572 has a single opening in correspondenceto all of the first pixels P1, all of the second pixels P2 or all of thethird pixels P3 in one pixel column. The opening of the second bank 572extends along the second direction Y, and a length of the opening in thesecond bank 572 in the second direction Y is larger than a length of theopening in the second bank 572 in the first direction X.

The first bank 570 may include a hydrophilic material to have ahydrophilic property. The second bank 572 may include a first pattern(not shown) including a hydrophilic material and a second pattern (notshown) including a hydrophobic material and positioned on the firstpattern. In this instance, the first pattern may include the samematerial as the first bank 570 and may extend from the first bank 570.The second bank 572 may include the second pattern without the firstpattern.

A first partition wall 582 being across a pixel column of the secondpixel P2 is disposed in the second pixel P2 along the second directionY. Namely, the second pixel P2 is divided into two regions by the firstpartition wall 582.

In addition, a second partition wall 584 being across a pixel column ofthe third pixels P3 is disposed in the third pixel P3 along the seconddirection Y. Namely, the third pixel P3 is divided into two regions bythe second partition wall 584.

The second bank 572 may have a fourth width W4, and each of the firstand second partition walls 582 and 584 may have a fifth width W5 equalto or smaller than the fourth width W4. The first partition wall 582 mayhas a width being equal to or larger than the second partition wall 584.

Each of the first and second partition walls 582 and 584 has adiscontinuous shape. Namely, the first and second partition walls 582and 584 respectively have first and second gaps G1 and G2.

The first gap G1 corresponds to a portion of the second pixel P2, andthe second gap G2 corresponds to a portion of the third pixel P3.Namely, the first gap G1 is positioned between adjacent two first banks570 in the pixel column of the second pixels P2, and the second gap G2is positioned between adjacent two first banks 570 in the pixel columnof the third pixels P3.

The first gap G1 provides a flow path of the fluid, i.e., an emittingmaterial solution, in the pixel column of the second pixels P2 such thatthe thickness uniformity of the light emitting layer of the lightemitting diode in the second pixel P2 is improved. In addition, thesecond gap G2 provides a flow path of the fluid, i.e., an emittingmaterial solution, in the pixel column of the third pixels P3 such thatthe thickness uniformity of the light emitting layer of the lightemitting diode in the third pixel P3 is improved.

In FIG. 9, the first and second partition walls 582 and 584 arerespectively disposed in the second and third pixels P2 and P3.Alternatively, the second partition wall 584 formed in the third pixelP3, which has a width being smaller than the second pixel P2, may beomitted.

In FIG. 9, the first and second partition walls 582 and 584 areconnected to the second bank 572 at an end of each of the pixel columnof the second pixels P2 and the pixel column of the third pixels P3.Alternatively, at least one of the first and second partition walls 582and 584 may be spaced apart from the second bank 572 at the end of eachof the pixel column of the second pixels P2 and the pixel column of thethird pixels P3.

In addition, a dummy pixel may be disposed at both ends of the pixelcolumn of the first pixels P1 arranged in the second direction, at bothends of the pixel column of the second pixels P2 arranged in the seconddirection, and at both ends of the pixel column of the third pixels P3arranged in the second direction.

In the EL display device of the present disclosure, the light emittingdiode including the light emitting layer are formed in each of thepixels P1, P2, and P3, and the light emitting layer is formed by asolution process. Namely, the light emitting layer can be formed by asolution process without a mask such that the manufacturing cost of theEL display device is reduced and the EL display device having a largesize and high resolution can be provided.

In addition, since the light emitting layers having the same color areintegrally formed to be connected to each other, variations (ordeviations) in the dropping amount of nozzles can be reduced, and athickness of the light emitting layer in each pixel can be uniform.

Moreover, since the first and second partition walls 582 and 584 arerespectively formed in the second and third pixels P2 and P3, each ofwhich has a width in the first direction X being larger than the firstpixel P1, the solution shift problem in the second and third pixels P2and P3 is prevented or minimized.

Furthermore, since a flow path of the fluid is provided by the first andsecond gaps G1 and G2 of the first and second partition walls 582 and584, the thickness uniformity of the light emitting layer in the secondand third pixels P2 and P3 is further improved.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. An electroluminescent display device, comprising:a substrate including a first pixel column and a second pixel column,wherein the first pixel column and the second pixel column respectivelyinclude a plurality of first pixels and a plurality of second pixelsarranged in a first direction and respectively have a first width and asecond width in a second direction perpendicular to the first direction,and wherein the second pixel column is positioned in the seconddirection from the first pixel column, and the second width is greaterthan the first width; a light emitting diode in each first pixel fromthe plurality of first pixels and each second pixel from the pluralityof second pixels, the light emitting diode including a first electrode,a light emitting layer and a second electrode; a first bank positionedbetween adjacent first pixels from the plurality of first pixels andbetween adjacent second pixels from the plurality of second pixels andcovering an edge of the first electrode; a second bank positionedbetween the first pixel column and the second pixel column and extendingalong the first direction; and a first partition wall being across thesecond pixel column along the first direction and positioned on thefirst electrode.
 2. The electroluminescent display device according toclaim 1, wherein the substrate further includes a third pixel columnincluding a plurality of third pixels arranged in the first directionand has a third width in the second direction, wherein theelectroluminescent display device further comprises: a second partitionwall being across the third pixel column along the first direction andpositioned on the first electrode, and wherein the third pixel column ispositioned in the second direction from the second pixel column, and thethird width is greater than the first width and smaller than the secondwidth.
 3. The electroluminescent display device according to claim 2,wherein each of the first partition wall and the second partition wallextends from the second bank.
 4. The electroluminescent display deviceaccording to claim 2, wherein the first partition wall is spaced apartfrom the second bank by a first distance, and the second partition wallis spaced apart from the second bank by a second distance, and whereinthe first distance is equal to or larger than the second distance. 5.The electroluminescent display device according to claim 2, wherein thefirst pixel column further includes a first dummy pixel, the secondpixel column further includes a second dummy pixel, and the third pixelcolumn further includes a third dummy pixel.
 6. The electroluminescentdisplay device according to claim 5, wherein the first partition wallextends into a portion of the second dummy pixel to have a firstdistance from the second bank, and the second partition wall extendsinto a portion of the third dummy pixel to have a second distance fromthe second bank, wherein the first distance is equal to or larger thanthe second distance.
 7. The electroluminescent display device accordingto claim 5, wherein the first partition wall and the second partitionwalls are respectively spaced apart from the second bank by the firstdummy pixel and the second dummy pixel.
 8. The electroluminescentdisplay device according to claim 2, wherein the second partition wallhas a width being equal to or smaller than the first partition wall. 9.The electroluminescent display device according to claim 1, wherein thefirst partition wall extends from the second bank.
 10. Theelectroluminescent display device according to claim 1, wherein thefirst partition wall is spaced apart from the second bank.
 11. Theelectroluminescent display device according to claim 1, wherein thefirst partition wall has a width being equal to or less than a width ofthe second bank.
 12. The electroluminescent display device according toclaim 1, wherein the first partition wall has a height being equal to orless than a height of the second bank.
 13. The electroluminescentdisplay device according to claim 1, wherein the first partition wallincludes a first gap corresponding to the first bank.
 14. Theelectroluminescent display device according to claim 13, wherein thefirst gap corresponds to the second pixel.
 15. The electroluminescentdisplay device according to claim 1, wherein the second pixel columnfurther includes a dummy pixel at both ends.
 16. The electroluminescentdisplay device according to claim 15, wherein the first partition wallextends into the dummy pixel.
 17. The electroluminescent display deviceaccording to claim 15, wherein the first partition wall is spaced apartfrom the second bank by the dummy pixel.
 18. The electroluminescentdisplay device according to claim 1, wherein the second pixel is dividedinto first region and a second region by the first partition wall,wherein the first electrode in the first region and the first electrodein the second region are connected to each other, and the light emittinglayer in the first region and the light emitting layer in the secondregion are separated from each other.
 19. The electroluminescent displaydevice according to claim 1, wherein the light emitting layers in thesecond pixel column are continuous in adjacent second pixels and areseparated in one second pixel by the first partition wall.
 20. Theelectroluminescent display device according to claim 15, furthercomprising: a thin film transistor between the substrate and the firstelectrode, wherein the first electrode is connected to the thin filmtransistor.
 21. The electroluminescent display device according to claim2, wherein the second partition wall includes a second gap correspondingto the first bank.
 22. The electroluminescent display device accordingto claim 21, wherein the second gap corresponds to the third pixel. 23.The electroluminescent display device according to claim 1, wherein thelight emitting layer is formed by a solution process without a mask.